Philippe Thalmann Questions around the environmental footprint of housing Philippe Thalmann EPFL Input for the SDSN Switzerland and NRP 73 ‘Sustainable economy ' workshop: 'Sustainable construction & housing '
Philippe Thalmann Question 1 IS HOUSING CONSTRUCTION NEEDED ANY MORE? 2
Population Philippe Thalmann scenarios FSO 2020 • Population growth is expected to slow down (1/2 of today's rate in 2050 in Scenario A) • No more growth after 2040 (Scenario C)? • It depends essentially on immigration 3
Scenarios for households Philippe Thalmann • More important for the housing stock is the number of households • Similar scenarios, with a slowdown in growth 4
Ratio of population to total number of dwellings Philippe Thalmann • The number of persons per dwelling reached a 1.89 floor • This means, that the same population will NOT occupy more dwellings 5
Scenarios for households by size Philippe Thalmann • The new households will be very small households • If they could share dwellings, the need for new dwellings would rise much less 6
Size of dwellings by construction period Philippe Thalmann Evolution of the surface of the dwellings m2/dwelling based on the construction year 110 100 90 80 • From 1945 until about 2005, the 70 surface of 60 dwellings was 50 rising 40 30 20 <1920 1920-1929 1930-1939 1940-1949 1950-1959 1960-1969 1970-1979 1980-1989 1990-1999 2000-2009 2010-2020 ABZ SCHL SM Source: data collected from the SHEF project partners 7
Age of dwellings Philippe Thalmann • 1/2 dwellings are over 50 years old • This shows a potential for reconstruction … or the lack of reconstruction Data: OFS je-f-09.03.00.14 8
Numbers of dwellings built, transformed, Philippe Thalmann demolished • Demolition- reconstruction is nearly irrelevant Propres calculs à partir de OFS Tab. 9.1.1 9
Spending on new construction and existing Philippe Thalmann dwellings • Spending on existing dwellings (essentially for renovation) is still very low 10
So, is housing construction needed any more? Philippe Thalmann • The need for new dwellings is shrinking • The demand for second and third homes is only slightly mitigating this, as is demolition-reconstruction • Households get smaller and smaller, while dwellings get larger and larger • If this trend were reversed and the existing housing stock used more efficiently, it could accommodate most of the population growth • More should be spent on improving the existing stock 11
Philippe Thalmann Question 2 HOW SHOULD THE EXISTING HOUSING STOCK BE IMPROVED? 12
Energy performance of housing stock Philippe Thalmann Distribution of housing energy reference area per energy efficiency class in 2015, depending on construction period • There are still many energy inefficient buildings • They mostly burn fossil energy • Low rate of (energy) refurbishment (about 1%/year) Source: estimation by Arzoyan, Oberpriller, Thalmann, Vielle (work in progress), using data from SFOE 13
Price of heating oil Philippe Thalmann • Heating oil is cheap despite rising CO 2 tax 14
The problems with energy refurbishment Philippe Thalmann • At the current low price of heating oil, energy refurbishment costs passed on to the tenant are not offset by his reduced energy bill • Split incentives: the owner determines the bulk of energy use; the tenant pays the bulk of the energy bill • When rents did not follow the decrease in the reference interest rate, they can not be raised after refurbishment • Energy refurbishment pays neither for owner, nor for tenant (hence the Buildings Program and cantonal regulation) 15
Other measures designed to improve the Philippe Thalmann sustainability of housing • Who pays for – the most energy efficient appliances in dwellings? – renewable electricity generation on buildings? – bio-diversity around the buildings and rooftop vegetation? – advanced waste sorting, composting, shared gardens? – for social infrastructure such as activity rooms, bicycle and car sharing, neighbourhood shops? • Maybe the solution is income diversity and burden sharing: tenants who can pay more (for the sustainability) pay more 16
Tenants' interest for sustainability Philippe Thalmann What are the tenants of ABZ, SCHL, Mobiliar looking for? • When invited to pick the 3 most important • Sustainability characteristics of their ideal dwelling among 23, only 13% picked 'ecological (e.g. characteristics rank Minergie)'; the favourite picks were 'low rent', low among tenants' 'with balcony', 'green spaces', and 'quiet' housing choice criteria • 45% know that their dwelling is better than • Only about 1/5 of the average energy wise (Minergie, renewable energy, etc.) tenants seem to care • Of these 45%, 44% indicate that this • This could change or overperformance was a criterion for picking be changed their dwelling Survey conducted by SHEF team among the tenants of ABZ, SCHL and Mobiliar between September and November 2019. 968 answers 17
So, how should the existing housing stock be Philippe Thalmann improved? • Under current conditions, energy refurbishments are difficult to justify on economic grounds • So are most of the investments that make a building or neighbourhood more sustainable • As the environmental footprint of housing, outside of energy, is essentially proportional to the housing area, fewer m 2 per inhabitant are a natural way to reduce it • May be a more holistic view is needed… 18
Philippe Thalmann Question 3 HOW CAN LANDLORDS MAKE THEIR TENANTS' LIFE MORE SUSTAINABLE? 19
Total environmental footprint of housing Philippe Thalmann Tenants contribute to the environmental footprint of housing: • How they choose a dwelling • How they use their dwelling • What they do with their non-rent money 20
Carbon footprint of consumption, incl. housing Philippe Thalmann • The carbon footprint of inhabitants of densely populated municipalities is 2/3 of those of thinly populated municipalities • Transportation is as important as housing as a source of CO 2 ; food comes next Froemelt, Andreas, René Buffat, and Stefanie Hellweg. "Machine learning based modeling of households: A regionalized bottom ‐ up approach to investigate consumption ‐ induced environmental impacts." Journal of Industrial Ecology (2019). 21
Induced consumption Philippe Thalmann • When tenants need to spend less for rent, they use a large part of these savings for travel, in particular air travel • This is especially true in higher income segments Froemelt, Andreas, Rhythima Shinde, and Stefanie Hellweg 22
So, how can landlords make their tenants' life Philippe Thalmann more sustainable? • Lowering rents could be bad for the environment ! • If sustainability in the buildings raises rents, this doubles the environmental gain ! • Tenants could be induced to accept smaller dwellings through lower rents, but that would again free more income for other spending… • Just as the environmental footprint of people depends on their housing and many other choices they make, it cannot be reduced by measures in housing alone THANK YOU FOR YOUR ATTENTION 23
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